A high-resolution interpolator for incremental encoders based on the quadrature PLL method

This paper presents a new high-resolution interpolator for incremental encoders based on the quadrature phase-locked loop method proposed by Emura, Until now this method has been applied to controllers of high-precision servomechanisms and has shown excellent performance. In this paper, we apply the method for the first time to an interpolator for incremental encoders. The experimental results show that high-speed interpolation is possible, with a maximum output frequency of 25 MHz-20 times higher than that of conventional interpolators, The interpolator proposed was also tested for noise rejection with a high-speed numerically controlled gear grinding machine, and has shown good noise rejection capability. This paper presents the design of the interpolator and the experimental results.